Most government jobs in the UK require this too. However, they don't require a spotless record but there would be some types of offences (serious fraud, affiliation with organised crime, etc) that would make it impossible. It's assessed based on the job, the offence, and how long ago it was.

Does a background check in the US imply that they'd never consider anyone with any blemish on their record whatsoever? Surely it just means they have to make an informed decision.